diff options
| author | Sandipan Das <sandipan.das@amd.com> | 2024-01-29 16:36:26 +0530 |
|---|---|---|
| committer | Sasha Levin <sashal@kernel.org> | 2024-03-26 18:20:56 -0400 |
| commit | 4fd4a210de9dc4fcaafcc571893d41039875a699 (patch) | |
| tree | 9edccec0b230df88934047c201c363fdd790fcb0 | |
| parent | 889846dfc8ee2cf31148a44bfd2faeb2faadc685 (diff) | |
perf/x86/amd/core: Avoid register reset when CPU is dead
[ Upstream commit ad8c91282c95f801c37812d59d2d9eba6899b384 ]
When bringing a CPU online, some of the PMC and LBR related registers
are reset. The same is done when a CPU is taken offline although that
is unnecessary. This currently happens in the "cpu_dead" callback which
is also incorrect as the callback runs on a control CPU instead of the
one that is being taken offline. This also affects hibernation and
suspend to RAM on some platforms as reported in the link below.
Fixes: 21d59e3e2c40 ("perf/x86/amd/core: Detect PerfMonV2 support")
Reported-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Sandipan Das <sandipan.das@amd.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/550a026764342cf7e5812680e3e2b91fe662b5ac.1706526029.git.sandipan.das@amd.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | arch/x86/events/amd/core.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c index 04f4b96dec6d..fd091b9dd706 100644 --- a/arch/x86/events/amd/core.c +++ b/arch/x86/events/amd/core.c @@ -604,7 +604,6 @@ static void amd_pmu_cpu_dead(int cpu) kfree(cpuhw->lbr_sel); cpuhw->lbr_sel = NULL; - amd_pmu_cpu_reset(cpu); if (!x86_pmu.amd_nb_constraints) return; |